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perf bpf: Move perf_event_output() from stdio.h to bpf.h
[linux/fpc-iii.git] / net / netlink / af_netlink.c
blob6bb9f3cde0b0d82af00a6b4f212be8c0d385dd47
1 /*
2 * NETLINK Kernel-user communication protocol.
3 *
4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
6 * Patrick McHardy <kaber@trash.net>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
14 * added netlink_proto_exit
15 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
16 * use nlk_sk, as sk->protinfo is on a diet 8)
17 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
18 * - inc module use count of module that owns
19 * the kernel socket in case userspace opens
20 * socket of same protocol
21 * - remove all module support, since netlink is
22 * mandatory if CONFIG_NET=y these days
23 */
24
25 #include <linux/module.h>
26
27 #include <linux/capability.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/signal.h>
31 #include <linux/sched.h>
32 #include <linux/errno.h>
33 #include <linux/string.h>
34 #include <linux/stat.h>
35 #include <linux/socket.h>
36 #include <linux/un.h>
37 #include <linux/fcntl.h>
38 #include <linux/termios.h>
39 #include <linux/sockios.h>
40 #include <linux/net.h>
41 #include <linux/fs.h>
42 #include <linux/slab.h>
43 #include <linux/uaccess.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
55 #include <linux/mm.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58 #include <linux/mutex.h>
59 #include <linux/vmalloc.h>
60 #include <linux/if_arp.h>
61 #include <linux/rhashtable.h>
62 #include <asm/cacheflush.h>
63 #include <linux/hash.h>
64 #include <linux/genetlink.h>
65 #include <linux/net_namespace.h>
66 #include <linux/nospec.h>
67
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/sock.h>
71 #include <net/scm.h>
72 #include <net/netlink.h>
73
74 #include "af_netlink.h"
75
76 struct listeners {
77 struct rcu_head rcu;
78 unsigned long masks[0];
79 };
80
81 /* state bits */
82 #define NETLINK_S_CONGESTED 0x0
83
84 static inline int netlink_is_kernel(struct sock *sk)
85 {
86 return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
87 }
88
89 struct netlink_table *nl_table __read_mostly;
90 EXPORT_SYMBOL_GPL(nl_table);
91
92 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
93
94 static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
95
96 static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
97 "nlk_cb_mutex-ROUTE",
98 "nlk_cb_mutex-1",
99 "nlk_cb_mutex-USERSOCK",
100 "nlk_cb_mutex-FIREWALL",
101 "nlk_cb_mutex-SOCK_DIAG",
102 "nlk_cb_mutex-NFLOG",
103 "nlk_cb_mutex-XFRM",
104 "nlk_cb_mutex-SELINUX",
105 "nlk_cb_mutex-ISCSI",
106 "nlk_cb_mutex-AUDIT",
107 "nlk_cb_mutex-FIB_LOOKUP",
108 "nlk_cb_mutex-CONNECTOR",
109 "nlk_cb_mutex-NETFILTER",
110 "nlk_cb_mutex-IP6_FW",
111 "nlk_cb_mutex-DNRTMSG",
112 "nlk_cb_mutex-KOBJECT_UEVENT",
113 "nlk_cb_mutex-GENERIC",
114 "nlk_cb_mutex-17",
115 "nlk_cb_mutex-SCSITRANSPORT",
116 "nlk_cb_mutex-ECRYPTFS",
117 "nlk_cb_mutex-RDMA",
118 "nlk_cb_mutex-CRYPTO",
119 "nlk_cb_mutex-SMC",
120 "nlk_cb_mutex-23",
121 "nlk_cb_mutex-24",
122 "nlk_cb_mutex-25",
123 "nlk_cb_mutex-26",
124 "nlk_cb_mutex-27",
125 "nlk_cb_mutex-28",
126 "nlk_cb_mutex-29",
127 "nlk_cb_mutex-30",
128 "nlk_cb_mutex-31",
129 "nlk_cb_mutex-MAX_LINKS"
130 };
131
132 static int netlink_dump(struct sock *sk);
133
134 /* nl_table locking explained:
135 * Lookup and traversal are protected with an RCU read-side lock. Insertion
136 * and removal are protected with per bucket lock while using RCU list
137 * modification primitives and may run in parallel to RCU protected lookups.
138 * Destruction of the Netlink socket may only occur *after* nl_table_lock has
139 * been acquired * either during or after the socket has been removed from
140 * the list and after an RCU grace period.
141 */
142 DEFINE_RWLOCK(nl_table_lock);
143 EXPORT_SYMBOL_GPL(nl_table_lock);
144 static atomic_t nl_table_users = ATOMIC_INIT(0);
145
146 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
147
148 static BLOCKING_NOTIFIER_HEAD(netlink_chain);
149
150
151 static const struct rhashtable_params netlink_rhashtable_params;
152
153 static inline u32 netlink_group_mask(u32 group)
154 {
155 return group ? 1 << (group - 1) : 0;
156 }
157
158 static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
159 gfp_t gfp_mask)
160 {
161 unsigned int len = skb_end_offset(skb);
162 struct sk_buff *new;
163
164 new = alloc_skb(len, gfp_mask);
165 if (new == NULL)
166 return NULL;
167
168 NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
169 NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
170 NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
171
172 skb_put_data(new, skb->data, len);
173 return new;
174 }
175
176 static unsigned int netlink_tap_net_id;
177
178 struct netlink_tap_net {
179 struct list_head netlink_tap_all;
180 struct mutex netlink_tap_lock;
181 };
182
183 int netlink_add_tap(struct netlink_tap *nt)
184 {
185 struct net *net = dev_net(nt->dev);
186 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
187
188 if (unlikely(nt->dev->type != ARPHRD_NETLINK))
189 return -EINVAL;
190
191 mutex_lock(&nn->netlink_tap_lock);
192 list_add_rcu(&nt->list, &nn->netlink_tap_all);
193 mutex_unlock(&nn->netlink_tap_lock);
194
195 __module_get(nt->module);
196
197 return 0;
198 }
199 EXPORT_SYMBOL_GPL(netlink_add_tap);
200
201 static int __netlink_remove_tap(struct netlink_tap *nt)
202 {
203 struct net *net = dev_net(nt->dev);
204 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
205 bool found = false;
206 struct netlink_tap *tmp;
207
208 mutex_lock(&nn->netlink_tap_lock);
209
210 list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
211 if (nt == tmp) {
212 list_del_rcu(&nt->list);
213 found = true;
214 goto out;
215 }
216 }
217
218 pr_warn("__netlink_remove_tap: %p not found\n", nt);
219 out:
220 mutex_unlock(&nn->netlink_tap_lock);
221
222 if (found)
223 module_put(nt->module);
224
225 return found ? 0 : -ENODEV;
226 }
227
228 int netlink_remove_tap(struct netlink_tap *nt)
229 {
230 int ret;
231
232 ret = __netlink_remove_tap(nt);
233 synchronize_net();
234
235 return ret;
236 }
237 EXPORT_SYMBOL_GPL(netlink_remove_tap);
238
239 static __net_init int netlink_tap_init_net(struct net *net)
240 {
241 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
242
243 INIT_LIST_HEAD(&nn->netlink_tap_all);
244 mutex_init(&nn->netlink_tap_lock);
245 return 0;
246 }
247
248 static void __net_exit netlink_tap_exit_net(struct net *net)
249 {
250 }
251
252 static struct pernet_operations netlink_tap_net_ops = {
253 .init = netlink_tap_init_net,
254 .exit = netlink_tap_exit_net,
255 .id = &netlink_tap_net_id,
256 .size = sizeof(struct netlink_tap_net),
257 };
258
259 static bool netlink_filter_tap(const struct sk_buff *skb)
260 {
261 struct sock *sk = skb->sk;
262
263 /* We take the more conservative approach and
264 * whitelist socket protocols that may pass.
265 */
266 switch (sk->sk_protocol) {
267 case NETLINK_ROUTE:
268 case NETLINK_USERSOCK:
269 case NETLINK_SOCK_DIAG:
270 case NETLINK_NFLOG:
271 case NETLINK_XFRM:
272 case NETLINK_FIB_LOOKUP:
273 case NETLINK_NETFILTER:
274 case NETLINK_GENERIC:
275 return true;
276 }
277
278 return false;
279 }
280
281 static int __netlink_deliver_tap_skb(struct sk_buff *skb,
282 struct net_device *dev)
283 {
284 struct sk_buff *nskb;
285 struct sock *sk = skb->sk;
286 int ret = -ENOMEM;
287
288 if (!net_eq(dev_net(dev), sock_net(sk)))
289 return 0;
290
291 dev_hold(dev);
292
293 if (is_vmalloc_addr(skb->head))
294 nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
295 else
296 nskb = skb_clone(skb, GFP_ATOMIC);
297 if (nskb) {
298 nskb->dev = dev;
299 nskb->protocol = htons((u16) sk->sk_protocol);
300 nskb->pkt_type = netlink_is_kernel(sk) ?
301 PACKET_KERNEL : PACKET_USER;
302 skb_reset_network_header(nskb);
303 ret = dev_queue_xmit(nskb);
304 if (unlikely(ret > 0))
305 ret = net_xmit_errno(ret);
306 }
307
308 dev_put(dev);
309 return ret;
310 }
311
312 static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn)
313 {
314 int ret;
315 struct netlink_tap *tmp;
316
317 if (!netlink_filter_tap(skb))
318 return;
319
320 list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) {
321 ret = __netlink_deliver_tap_skb(skb, tmp->dev);
322 if (unlikely(ret))
323 break;
324 }
325 }
326
327 static void netlink_deliver_tap(struct net *net, struct sk_buff *skb)
328 {
329 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
330
331 rcu_read_lock();
332
333 if (unlikely(!list_empty(&nn->netlink_tap_all)))
334 __netlink_deliver_tap(skb, nn);
335
336 rcu_read_unlock();
337 }
338
339 static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
340 struct sk_buff *skb)
341 {
342 if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
343 netlink_deliver_tap(sock_net(dst), skb);
344 }
345
346 static void netlink_overrun(struct sock *sk)
347 {
348 struct netlink_sock *nlk = nlk_sk(sk);
349
350 if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
351 if (!test_and_set_bit(NETLINK_S_CONGESTED,
352 &nlk_sk(sk)->state)) {
353 sk->sk_err = ENOBUFS;
354 sk->sk_error_report(sk);
355 }
356 }
357 atomic_inc(&sk->sk_drops);
358 }
359
360 static void netlink_rcv_wake(struct sock *sk)
361 {
362 struct netlink_sock *nlk = nlk_sk(sk);
363
364 if (skb_queue_empty(&sk->sk_receive_queue))
365 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
366 if (!test_bit(NETLINK_S_CONGESTED, &nlk->state))
367 wake_up_interruptible(&nlk->wait);
368 }
369
370 static void netlink_skb_destructor(struct sk_buff *skb)
371 {
372 if (is_vmalloc_addr(skb->head)) {
373 if (!skb->cloned ||
374 !atomic_dec_return(&(skb_shinfo(skb)->dataref)))
375 vfree(skb->head);
376
377 skb->head = NULL;
378 }
379 if (skb->sk != NULL)
380 sock_rfree(skb);
381 }
382
383 static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
384 {
385 WARN_ON(skb->sk != NULL);
386 skb->sk = sk;
387 skb->destructor = netlink_skb_destructor;
388 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
389 sk_mem_charge(sk, skb->truesize);
390 }
391
392 static void netlink_sock_destruct(struct sock *sk)
393 {
394 struct netlink_sock *nlk = nlk_sk(sk);
395
396 if (nlk->cb_running) {
397 if (nlk->cb.done)
398 nlk->cb.done(&nlk->cb);
399 module_put(nlk->cb.module);
400 kfree_skb(nlk->cb.skb);
401 }
402
403 skb_queue_purge(&sk->sk_receive_queue);
404
405 if (!sock_flag(sk, SOCK_DEAD)) {
406 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
407 return;
408 }
409
410 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
411 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
412 WARN_ON(nlk_sk(sk)->groups);
413 }
414
415 static void netlink_sock_destruct_work(struct work_struct *work)
416 {
417 struct netlink_sock *nlk = container_of(work, struct netlink_sock,
418 work);
419
420 sk_free(&nlk->sk);
421 }
422
423 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
424 * SMP. Look, when several writers sleep and reader wakes them up, all but one
425 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
426 * this, _but_ remember, it adds useless work on UP machines.
427 */
428
429 void netlink_table_grab(void)
430 __acquires(nl_table_lock)
431 {
432 might_sleep();
433
434 write_lock_irq(&nl_table_lock);
435
436 if (atomic_read(&nl_table_users)) {
437 DECLARE_WAITQUEUE(wait, current);
438
439 add_wait_queue_exclusive(&nl_table_wait, &wait);
440 for (;;) {
441 set_current_state(TASK_UNINTERRUPTIBLE);
442 if (atomic_read(&nl_table_users) == 0)
443 break;
444 write_unlock_irq(&nl_table_lock);
445 schedule();
446 write_lock_irq(&nl_table_lock);
447 }
448
449 __set_current_state(TASK_RUNNING);
450 remove_wait_queue(&nl_table_wait, &wait);
451 }
452 }
453
454 void netlink_table_ungrab(void)
455 __releases(nl_table_lock)
456 {
457 write_unlock_irq(&nl_table_lock);
458 wake_up(&nl_table_wait);
459 }
460
461 static inline void
462 netlink_lock_table(void)
463 {
464 /* read_lock() synchronizes us to netlink_table_grab */
465
466 read_lock(&nl_table_lock);
467 atomic_inc(&nl_table_users);
468 read_unlock(&nl_table_lock);
469 }
470
471 static inline void
472 netlink_unlock_table(void)
473 {
474 if (atomic_dec_and_test(&nl_table_users))
475 wake_up(&nl_table_wait);
476 }
477
478 struct netlink_compare_arg
479 {
480 possible_net_t pnet;
481 u32 portid;
482 };
483
484 /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
485 #define netlink_compare_arg_len \
486 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
487
488 static inline int netlink_compare(struct rhashtable_compare_arg *arg,
489 const void *ptr)
490 {
491 const struct netlink_compare_arg *x = arg->key;
492 const struct netlink_sock *nlk = ptr;
493
494 return nlk->portid != x->portid ||
495 !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet));
496 }
497
498 static void netlink_compare_arg_init(struct netlink_compare_arg *arg,
499 struct net *net, u32 portid)
500 {
501 memset(arg, 0, sizeof(*arg));
502 write_pnet(&arg->pnet, net);
503 arg->portid = portid;
504 }
505
506 static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
507 struct net *net)
508 {
509 struct netlink_compare_arg arg;
510
511 netlink_compare_arg_init(&arg, net, portid);
512 return rhashtable_lookup_fast(&table->hash, &arg,
513 netlink_rhashtable_params);
514 }
515
516 static int __netlink_insert(struct netlink_table *table, struct sock *sk)
517 {
518 struct netlink_compare_arg arg;
519
520 netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid);
521 return rhashtable_lookup_insert_key(&table->hash, &arg,
522 &nlk_sk(sk)->node,
523 netlink_rhashtable_params);
524 }
525
526 static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
527 {
528 struct netlink_table *table = &nl_table[protocol];
529 struct sock *sk;
530
531 rcu_read_lock();
532 sk = __netlink_lookup(table, portid, net);
533 if (sk)
534 sock_hold(sk);
535 rcu_read_unlock();
536
537 return sk;
538 }
539
540 static const struct proto_ops netlink_ops;
541
542 static void
543 netlink_update_listeners(struct sock *sk)
544 {
545 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
546 unsigned long mask;
547 unsigned int i;
548 struct listeners *listeners;
549
550 listeners = nl_deref_protected(tbl->listeners);
551 if (!listeners)
552 return;
553
554 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
555 mask = 0;
556 sk_for_each_bound(sk, &tbl->mc_list) {
557 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
558 mask |= nlk_sk(sk)->groups[i];
559 }
560 listeners->masks[i] = mask;
561 }
562 /* this function is only called with the netlink table "grabbed", which
563 * makes sure updates are visible before bind or setsockopt return. */
564 }
565
566 static int netlink_insert(struct sock *sk, u32 portid)
567 {
568 struct netlink_table *table = &nl_table[sk->sk_protocol];
569 int err;
570
571 lock_sock(sk);
572
573 err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
574 if (nlk_sk(sk)->bound)
575 goto err;
576
577 nlk_sk(sk)->portid = portid;
578 sock_hold(sk);
579
580 err = __netlink_insert(table, sk);
581 if (err) {
582 /* In case the hashtable backend returns with -EBUSY
583 * from here, it must not escape to the caller.
584 */
585 if (unlikely(err == -EBUSY))
586 err = -EOVERFLOW;
587 if (err == -EEXIST)
588 err = -EADDRINUSE;
589 sock_put(sk);
590 goto err;
591 }
592
593 /* We need to ensure that the socket is hashed and visible. */
594 smp_wmb();
595 nlk_sk(sk)->bound = portid;
596
597 err:
598 release_sock(sk);
599 return err;
600 }
601
602 static void netlink_remove(struct sock *sk)
603 {
604 struct netlink_table *table;
605
606 table = &nl_table[sk->sk_protocol];
607 if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node,
608 netlink_rhashtable_params)) {
609 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
610 __sock_put(sk);
611 }
612
613 netlink_table_grab();
614 if (nlk_sk(sk)->subscriptions) {
615 __sk_del_bind_node(sk);
616 netlink_update_listeners(sk);
617 }
618 if (sk->sk_protocol == NETLINK_GENERIC)
619 atomic_inc(&genl_sk_destructing_cnt);
620 netlink_table_ungrab();
621 }
622
623 static struct proto netlink_proto = {
624 .name = "NETLINK",
625 .owner = THIS_MODULE,
626 .obj_size = sizeof(struct netlink_sock),
627 };
628
629 static int __netlink_create(struct net *net, struct socket *sock,
630 struct mutex *cb_mutex, int protocol,
631 int kern)
632 {
633 struct sock *sk;
634 struct netlink_sock *nlk;
635
636 sock->ops = &netlink_ops;
637
638 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern);
639 if (!sk)
640 return -ENOMEM;
641
642 sock_init_data(sock, sk);
643
644 nlk = nlk_sk(sk);
645 if (cb_mutex) {
646 nlk->cb_mutex = cb_mutex;
647 } else {
648 nlk->cb_mutex = &nlk->cb_def_mutex;
649 mutex_init(nlk->cb_mutex);
650 lockdep_set_class_and_name(nlk->cb_mutex,
651 nlk_cb_mutex_keys + protocol,
652 nlk_cb_mutex_key_strings[protocol]);
653 }
654 init_waitqueue_head(&nlk->wait);
655
656 sk->sk_destruct = netlink_sock_destruct;
657 sk->sk_protocol = protocol;
658 return 0;
659 }
660
661 static int netlink_create(struct net *net, struct socket *sock, int protocol,
662 int kern)
663 {
664 struct module *module = NULL;
665 struct mutex *cb_mutex;
666 struct netlink_sock *nlk;
667 int (*bind)(struct net *net, int group);
668 void (*unbind)(struct net *net, int group);
669 int err = 0;
670
671 sock->state = SS_UNCONNECTED;
672
673 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
674 return -ESOCKTNOSUPPORT;
675
676 if (protocol < 0 || protocol >= MAX_LINKS)
677 return -EPROTONOSUPPORT;
678 protocol = array_index_nospec(protocol, MAX_LINKS);
679
680 netlink_lock_table();
681 #ifdef CONFIG_MODULES
682 if (!nl_table[protocol].registered) {
683 netlink_unlock_table();
684 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
685 netlink_lock_table();
686 }
687 #endif
688 if (nl_table[protocol].registered &&
689 try_module_get(nl_table[protocol].module))
690 module = nl_table[protocol].module;
691 else
692 err = -EPROTONOSUPPORT;
693 cb_mutex = nl_table[protocol].cb_mutex;
694 bind = nl_table[protocol].bind;
695 unbind = nl_table[protocol].unbind;
696 netlink_unlock_table();
697
698 if (err < 0)
699 goto out;
700
701 err = __netlink_create(net, sock, cb_mutex, protocol, kern);
702 if (err < 0)
703 goto out_module;
704
705 local_bh_disable();
706 sock_prot_inuse_add(net, &netlink_proto, 1);
707 local_bh_enable();
708
709 nlk = nlk_sk(sock->sk);
710 nlk->module = module;
711 nlk->netlink_bind = bind;
712 nlk->netlink_unbind = unbind;
713 out:
714 return err;
715
716 out_module:
717 module_put(module);
718 goto out;
719 }
720
721 static void deferred_put_nlk_sk(struct rcu_head *head)
722 {
723 struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu);
724 struct sock *sk = &nlk->sk;
725
726 kfree(nlk->groups);
727 nlk->groups = NULL;
728
729 if (!refcount_dec_and_test(&sk->sk_refcnt))
730 return;
731
732 if (nlk->cb_running && nlk->cb.done) {
733 INIT_WORK(&nlk->work, netlink_sock_destruct_work);
734 schedule_work(&nlk->work);
735 return;
736 }
737
738 sk_free(sk);
739 }
740
741 static int netlink_release(struct socket *sock)
742 {
743 struct sock *sk = sock->sk;
744 struct netlink_sock *nlk;
745
746 if (!sk)
747 return 0;
748
749 netlink_remove(sk);
750 sock_orphan(sk);
751 nlk = nlk_sk(sk);
752
753 /*
754 * OK. Socket is unlinked, any packets that arrive now
755 * will be purged.
756 */
757
758 /* must not acquire netlink_table_lock in any way again before unbind
759 * and notifying genetlink is done as otherwise it might deadlock
760 */
761 if (nlk->netlink_unbind) {
762 int i;
763
764 for (i = 0; i < nlk->ngroups; i++)
765 if (test_bit(i, nlk->groups))
766 nlk->netlink_unbind(sock_net(sk), i + 1);
767 }
768 if (sk->sk_protocol == NETLINK_GENERIC &&
769 atomic_dec_return(&genl_sk_destructing_cnt) == 0)
770 wake_up(&genl_sk_destructing_waitq);
771
772 sock->sk = NULL;
773 wake_up_interruptible_all(&nlk->wait);
774
775 skb_queue_purge(&sk->sk_write_queue);
776
777 if (nlk->portid && nlk->bound) {
778 struct netlink_notify n = {
779 .net = sock_net(sk),
780 .protocol = sk->sk_protocol,
781 .portid = nlk->portid,
782 };
783 blocking_notifier_call_chain(&netlink_chain,
784 NETLINK_URELEASE, &n);
785 }
786
787 module_put(nlk->module);
788
789 if (netlink_is_kernel(sk)) {
790 netlink_table_grab();
791 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
792 if (--nl_table[sk->sk_protocol].registered == 0) {
793 struct listeners *old;
794
795 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
796 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
797 kfree_rcu(old, rcu);
798 nl_table[sk->sk_protocol].module = NULL;
799 nl_table[sk->sk_protocol].bind = NULL;
800 nl_table[sk->sk_protocol].unbind = NULL;
801 nl_table[sk->sk_protocol].flags = 0;
802 nl_table[sk->sk_protocol].registered = 0;
803 }
804 netlink_table_ungrab();
805 }
806
807 local_bh_disable();
808 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
809 local_bh_enable();
810 call_rcu(&nlk->rcu, deferred_put_nlk_sk);
811 return 0;
812 }
813
814 static int netlink_autobind(struct socket *sock)
815 {
816 struct sock *sk = sock->sk;
817 struct net *net = sock_net(sk);
818 struct netlink_table *table = &nl_table[sk->sk_protocol];
819 s32 portid = task_tgid_vnr(current);
820 int err;
821 s32 rover = -4096;
822 bool ok;
823
824 retry:
825 cond_resched();
826 rcu_read_lock();
827 ok = !__netlink_lookup(table, portid, net);
828 rcu_read_unlock();
829 if (!ok) {
830 /* Bind collision, search negative portid values. */
831 if (rover == -4096)
832 /* rover will be in range [S32_MIN, -4097] */
833 rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
834 else if (rover >= -4096)
835 rover = -4097;
836 portid = rover--;
837 goto retry;
838 }
839
840 err = netlink_insert(sk, portid);
841 if (err == -EADDRINUSE)
842 goto retry;
843
844 /* If 2 threads race to autobind, that is fine. */
845 if (err == -EBUSY)
846 err = 0;
847
848 return err;
849 }
850
851 /**
852 * __netlink_ns_capable - General netlink message capability test
853 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
854 * @user_ns: The user namespace of the capability to use
855 * @cap: The capability to use
856 *
857 * Test to see if the opener of the socket we received the message
858 * from had when the netlink socket was created and the sender of the
859 * message has has the capability @cap in the user namespace @user_ns.
860 */
861 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
862 struct user_namespace *user_ns, int cap)
863 {
864 return ((nsp->flags & NETLINK_SKB_DST) ||
865 file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
866 ns_capable(user_ns, cap);
867 }
868 EXPORT_SYMBOL(__netlink_ns_capable);
869
870 /**
871 * netlink_ns_capable - General netlink message capability test
872 * @skb: socket buffer holding a netlink command from userspace
873 * @user_ns: The user namespace of the capability to use
874 * @cap: The capability to use
875 *
876 * Test to see if the opener of the socket we received the message
877 * from had when the netlink socket was created and the sender of the
878 * message has has the capability @cap in the user namespace @user_ns.
879 */
880 bool netlink_ns_capable(const struct sk_buff *skb,
881 struct user_namespace *user_ns, int cap)
882 {
883 return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
884 }
885 EXPORT_SYMBOL(netlink_ns_capable);
886
887 /**
888 * netlink_capable - Netlink global message capability test
889 * @skb: socket buffer holding a netlink command from userspace
890 * @cap: The capability to use
891 *
892 * Test to see if the opener of the socket we received the message
893 * from had when the netlink socket was created and the sender of the
894 * message has has the capability @cap in all user namespaces.
895 */
896 bool netlink_capable(const struct sk_buff *skb, int cap)
897 {
898 return netlink_ns_capable(skb, &init_user_ns, cap);
899 }
900 EXPORT_SYMBOL(netlink_capable);
901
902 /**
903 * netlink_net_capable - Netlink network namespace message capability test
904 * @skb: socket buffer holding a netlink command from userspace
905 * @cap: The capability to use
906 *
907 * Test to see if the opener of the socket we received the message
908 * from had when the netlink socket was created and the sender of the
909 * message has has the capability @cap over the network namespace of
910 * the socket we received the message from.
911 */
912 bool netlink_net_capable(const struct sk_buff *skb, int cap)
913 {
914 return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
915 }
916 EXPORT_SYMBOL(netlink_net_capable);
917
918 static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
919 {
920 return (nl_table[sock->sk->sk_protocol].flags & flag) ||
921 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
922 }
923
924 static void
925 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
926 {
927 struct netlink_sock *nlk = nlk_sk(sk);
928
929 if (nlk->subscriptions && !subscriptions)
930 __sk_del_bind_node(sk);
931 else if (!nlk->subscriptions && subscriptions)
932 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
933 nlk->subscriptions = subscriptions;
934 }
935
936 static int netlink_realloc_groups(struct sock *sk)
937 {
938 struct netlink_sock *nlk = nlk_sk(sk);
939 unsigned int groups;
940 unsigned long *new_groups;
941 int err = 0;
942
943 netlink_table_grab();
944
945 groups = nl_table[sk->sk_protocol].groups;
946 if (!nl_table[sk->sk_protocol].registered) {
947 err = -ENOENT;
948 goto out_unlock;
949 }
950
951 if (nlk->ngroups >= groups)
952 goto out_unlock;
953
954 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
955 if (new_groups == NULL) {
956 err = -ENOMEM;
957 goto out_unlock;
958 }
959 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
960 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
961
962 nlk->groups = new_groups;
963 nlk->ngroups = groups;
964 out_unlock:
965 netlink_table_ungrab();
966 return err;
967 }
968
969 static void netlink_undo_bind(int group, long unsigned int groups,
970 struct sock *sk)
971 {
972 struct netlink_sock *nlk = nlk_sk(sk);
973 int undo;
974
975 if (!nlk->netlink_unbind)
976 return;
977
978 for (undo = 0; undo < group; undo++)
979 if (test_bit(undo, &groups))
980 nlk->netlink_unbind(sock_net(sk), undo + 1);
981 }
982
983 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
984 int addr_len)
985 {
986 struct sock *sk = sock->sk;
987 struct net *net = sock_net(sk);
988 struct netlink_sock *nlk = nlk_sk(sk);
989 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
990 int err = 0;
991 unsigned long groups = nladdr->nl_groups;
992 bool bound;
993
994 if (addr_len < sizeof(struct sockaddr_nl))
995 return -EINVAL;
996
997 if (nladdr->nl_family != AF_NETLINK)
998 return -EINVAL;
999
1000 /* Only superuser is allowed to listen multicasts */
1001 if (groups) {
1002 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1003 return -EPERM;
1004 err = netlink_realloc_groups(sk);
1005 if (err)
1006 return err;
1007 }
1008
1009 if (nlk->ngroups < BITS_PER_LONG)
1010 groups &= (1UL << nlk->ngroups) - 1;
1011
1012 bound = nlk->bound;
1013 if (bound) {
1014 /* Ensure nlk->portid is up-to-date. */
1015 smp_rmb();
1016
1017 if (nladdr->nl_pid != nlk->portid)
1018 return -EINVAL;
1019 }
1020
1021 netlink_lock_table();
1022 if (nlk->netlink_bind && groups) {
1023 int group;
1024
1025 for (group = 0; group < nlk->ngroups; group++) {
1026 if (!test_bit(group, &groups))
1027 continue;
1028 err = nlk->netlink_bind(net, group + 1);
1029 if (!err)
1030 continue;
1031 netlink_undo_bind(group, groups, sk);
1032 goto unlock;
1033 }
1034 }
1035
1036 /* No need for barriers here as we return to user-space without
1037 * using any of the bound attributes.
1038 */
1039 if (!bound) {
1040 err = nladdr->nl_pid ?
1041 netlink_insert(sk, nladdr->nl_pid) :
1042 netlink_autobind(sock);
1043 if (err) {
1044 netlink_undo_bind(nlk->ngroups, groups, sk);
1045 goto unlock;
1046 }
1047 }
1048
1049 if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
1050 goto unlock;
1051 netlink_unlock_table();
1052
1053 netlink_table_grab();
1054 netlink_update_subscriptions(sk, nlk->subscriptions +
1055 hweight32(groups) -
1056 hweight32(nlk->groups[0]));
1057 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
1058 netlink_update_listeners(sk);
1059 netlink_table_ungrab();
1060
1061 return 0;
1062
1063 unlock:
1064 netlink_unlock_table();
1065 return err;
1066 }
1067
1068 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
1069 int alen, int flags)
1070 {
1071 int err = 0;
1072 struct sock *sk = sock->sk;
1073 struct netlink_sock *nlk = nlk_sk(sk);
1074 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
1075
1076 if (alen < sizeof(addr->sa_family))
1077 return -EINVAL;
1078
1079 if (addr->sa_family == AF_UNSPEC) {
1080 sk->sk_state = NETLINK_UNCONNECTED;
1081 nlk->dst_portid = 0;
1082 nlk->dst_group = 0;
1083 return 0;
1084 }
1085 if (addr->sa_family != AF_NETLINK)
1086 return -EINVAL;
1087
1088 if (alen < sizeof(struct sockaddr_nl))
1089 return -EINVAL;
1090
1091 if ((nladdr->nl_groups || nladdr->nl_pid) &&
1092 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1093 return -EPERM;
1094
1095 /* No need for barriers here as we return to user-space without
1096 * using any of the bound attributes.
1097 */
1098 if (!nlk->bound)
1099 err = netlink_autobind(sock);
1100
1101 if (err == 0) {
1102 sk->sk_state = NETLINK_CONNECTED;
1103 nlk->dst_portid = nladdr->nl_pid;
1104 nlk->dst_group = ffs(nladdr->nl_groups);
1105 }
1106
1107 return err;
1108 }
1109
1110 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
1111 int peer)
1112 {
1113 struct sock *sk = sock->sk;
1114 struct netlink_sock *nlk = nlk_sk(sk);
1115 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
1116
1117 nladdr->nl_family = AF_NETLINK;
1118 nladdr->nl_pad = 0;
1119
1120 if (peer) {
1121 nladdr->nl_pid = nlk->dst_portid;
1122 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
1123 } else {
1124 nladdr->nl_pid = nlk->portid;
1125 netlink_lock_table();
1126 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
1127 netlink_unlock_table();
1128 }
1129 return sizeof(*nladdr);
1130 }
1131
1132 static int netlink_ioctl(struct socket *sock, unsigned int cmd,
1133 unsigned long arg)
1134 {
1135 /* try to hand this ioctl down to the NIC drivers.
1136 */
1137 return -ENOIOCTLCMD;
1138 }
1139
1140 static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
1141 {
1142 struct sock *sock;
1143 struct netlink_sock *nlk;
1144
1145 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
1146 if (!sock)
1147 return ERR_PTR(-ECONNREFUSED);
1148
1149 /* Don't bother queuing skb if kernel socket has no input function */
1150 nlk = nlk_sk(sock);
1151 if (sock->sk_state == NETLINK_CONNECTED &&
1152 nlk->dst_portid != nlk_sk(ssk)->portid) {
1153 sock_put(sock);
1154 return ERR_PTR(-ECONNREFUSED);
1155 }
1156 return sock;
1157 }
1158
1159 struct sock *netlink_getsockbyfilp(struct file *filp)
1160 {
1161 struct inode *inode = file_inode(filp);
1162 struct sock *sock;
1163
1164 if (!S_ISSOCK(inode->i_mode))
1165 return ERR_PTR(-ENOTSOCK);
1166
1167 sock = SOCKET_I(inode)->sk;
1168 if (sock->sk_family != AF_NETLINK)
1169 return ERR_PTR(-EINVAL);
1170
1171 sock_hold(sock);
1172 return sock;
1173 }
1174
1175 static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
1176 int broadcast)
1177 {
1178 struct sk_buff *skb;
1179 void *data;
1180
1181 if (size <= NLMSG_GOODSIZE || broadcast)
1182 return alloc_skb(size, GFP_KERNEL);
1183
1184 size = SKB_DATA_ALIGN(size) +
1185 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1186
1187 data = vmalloc(size);
1188 if (data == NULL)
1189 return NULL;
1190
1191 skb = __build_skb(data, size);
1192 if (skb == NULL)
1193 vfree(data);
1194 else
1195 skb->destructor = netlink_skb_destructor;
1196
1197 return skb;
1198 }
1199
1200 /*
1201 * Attach a skb to a netlink socket.
1202 * The caller must hold a reference to the destination socket. On error, the
1203 * reference is dropped. The skb is not send to the destination, just all
1204 * all error checks are performed and memory in the queue is reserved.
1205 * Return values:
1206 * < 0: error. skb freed, reference to sock dropped.
1207 * 0: continue
1208 * 1: repeat lookup - reference dropped while waiting for socket memory.
1209 */
1210 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
1211 long *timeo, struct sock *ssk)
1212 {
1213 struct netlink_sock *nlk;
1214
1215 nlk = nlk_sk(sk);
1216
1217 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1218 test_bit(NETLINK_S_CONGESTED, &nlk->state))) {
1219 DECLARE_WAITQUEUE(wait, current);
1220 if (!*timeo) {
1221 if (!ssk || netlink_is_kernel(ssk))
1222 netlink_overrun(sk);
1223 sock_put(sk);
1224 kfree_skb(skb);
1225 return -EAGAIN;
1226 }
1227
1228 __set_current_state(TASK_INTERRUPTIBLE);
1229 add_wait_queue(&nlk->wait, &wait);
1230
1231 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1232 test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
1233 !sock_flag(sk, SOCK_DEAD))
1234 *timeo = schedule_timeout(*timeo);
1235
1236 __set_current_state(TASK_RUNNING);
1237 remove_wait_queue(&nlk->wait, &wait);
1238 sock_put(sk);
1239
1240 if (signal_pending(current)) {
1241 kfree_skb(skb);
1242 return sock_intr_errno(*timeo);
1243 }
1244 return 1;
1245 }
1246 netlink_skb_set_owner_r(skb, sk);
1247 return 0;
1248 }
1249
1250 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1251 {
1252 int len = skb->len;
1253
1254 netlink_deliver_tap(sock_net(sk), skb);
1255
1256 skb_queue_tail(&sk->sk_receive_queue, skb);
1257 sk->sk_data_ready(sk);
1258 return len;
1259 }
1260
1261 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1262 {
1263 int len = __netlink_sendskb(sk, skb);
1264
1265 sock_put(sk);
1266 return len;
1267 }
1268
1269 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
1270 {
1271 kfree_skb(skb);
1272 sock_put(sk);
1273 }
1274
1275 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
1276 {
1277 int delta;
1278
1279 WARN_ON(skb->sk != NULL);
1280 delta = skb->end - skb->tail;
1281 if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
1282 return skb;
1283
1284 if (skb_shared(skb)) {
1285 struct sk_buff *nskb = skb_clone(skb, allocation);
1286 if (!nskb)
1287 return skb;
1288 consume_skb(skb);
1289 skb = nskb;
1290 }
1291
1292 pskb_expand_head(skb, 0, -delta,
1293 (allocation & ~__GFP_DIRECT_RECLAIM) |
1294 __GFP_NOWARN | __GFP_NORETRY);
1295 return skb;
1296 }
1297
1298 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
1299 struct sock *ssk)
1300 {
1301 int ret;
1302 struct netlink_sock *nlk = nlk_sk(sk);
1303
1304 ret = -ECONNREFUSED;
1305 if (nlk->netlink_rcv != NULL) {
1306 ret = skb->len;
1307 netlink_skb_set_owner_r(skb, sk);
1308 NETLINK_CB(skb).sk = ssk;
1309 netlink_deliver_tap_kernel(sk, ssk, skb);
1310 nlk->netlink_rcv(skb);
1311 consume_skb(skb);
1312 } else {
1313 kfree_skb(skb);
1314 }
1315 sock_put(sk);
1316 return ret;
1317 }
1318
1319 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
1320 u32 portid, int nonblock)
1321 {
1322 struct sock *sk;
1323 int err;
1324 long timeo;
1325
1326 skb = netlink_trim(skb, gfp_any());
1327
1328 timeo = sock_sndtimeo(ssk, nonblock);
1329 retry:
1330 sk = netlink_getsockbyportid(ssk, portid);
1331 if (IS_ERR(sk)) {
1332 kfree_skb(skb);
1333 return PTR_ERR(sk);
1334 }
1335 if (netlink_is_kernel(sk))
1336 return netlink_unicast_kernel(sk, skb, ssk);
1337
1338 if (sk_filter(sk, skb)) {
1339 err = skb->len;
1340 kfree_skb(skb);
1341 sock_put(sk);
1342 return err;
1343 }
1344
1345 err = netlink_attachskb(sk, skb, &timeo, ssk);
1346 if (err == 1)
1347 goto retry;
1348 if (err)
1349 return err;
1350
1351 return netlink_sendskb(sk, skb);
1352 }
1353 EXPORT_SYMBOL(netlink_unicast);
1354
1355 int netlink_has_listeners(struct sock *sk, unsigned int group)
1356 {
1357 int res = 0;
1358 struct listeners *listeners;
1359
1360 BUG_ON(!netlink_is_kernel(sk));
1361
1362 rcu_read_lock();
1363 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
1364
1365 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
1366 res = test_bit(group - 1, listeners->masks);
1367
1368 rcu_read_unlock();
1369
1370 return res;
1371 }
1372 EXPORT_SYMBOL_GPL(netlink_has_listeners);
1373
1374 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
1375 {
1376 struct netlink_sock *nlk = nlk_sk(sk);
1377
1378 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
1379 !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
1380 netlink_skb_set_owner_r(skb, sk);
1381 __netlink_sendskb(sk, skb);
1382 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
1383 }
1384 return -1;
1385 }
1386
1387 struct netlink_broadcast_data {
1388 struct sock *exclude_sk;
1389 struct net *net;
1390 u32 portid;
1391 u32 group;
1392 int failure;
1393 int delivery_failure;
1394 int congested;
1395 int delivered;
1396 gfp_t allocation;
1397 struct sk_buff *skb, *skb2;
1398 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1399 void *tx_data;
1400 };
1401
1402 static void do_one_broadcast(struct sock *sk,
1403 struct netlink_broadcast_data *p)
1404 {
1405 struct netlink_sock *nlk = nlk_sk(sk);
1406 int val;
1407
1408 if (p->exclude_sk == sk)
1409 return;
1410
1411 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1412 !test_bit(p->group - 1, nlk->groups))
1413 return;
1414
1415 if (!net_eq(sock_net(sk), p->net)) {
1416 if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
1417 return;
1418
1419 if (!peernet_has_id(sock_net(sk), p->net))
1420 return;
1421
1422 if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
1423 CAP_NET_BROADCAST))
1424 return;
1425 }
1426
1427 if (p->failure) {
1428 netlink_overrun(sk);
1429 return;
1430 }
1431
1432 sock_hold(sk);
1433 if (p->skb2 == NULL) {
1434 if (skb_shared(p->skb)) {
1435 p->skb2 = skb_clone(p->skb, p->allocation);
1436 } else {
1437 p->skb2 = skb_get(p->skb);
1438 /*
1439 * skb ownership may have been set when
1440 * delivered to a previous socket.
1441 */
1442 skb_orphan(p->skb2);
1443 }
1444 }
1445 if (p->skb2 == NULL) {
1446 netlink_overrun(sk);
1447 /* Clone failed. Notify ALL listeners. */
1448 p->failure = 1;
1449 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1450 p->delivery_failure = 1;
1451 goto out;
1452 }
1453 if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1454 kfree_skb(p->skb2);
1455 p->skb2 = NULL;
1456 goto out;
1457 }
1458 if (sk_filter(sk, p->skb2)) {
1459 kfree_skb(p->skb2);
1460 p->skb2 = NULL;
1461 goto out;
1462 }
1463 NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
1464 if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
1465 NETLINK_CB(p->skb2).nsid_is_set = true;
1466 val = netlink_broadcast_deliver(sk, p->skb2);
1467 if (val < 0) {
1468 netlink_overrun(sk);
1469 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1470 p->delivery_failure = 1;
1471 } else {
1472 p->congested |= val;
1473 p->delivered = 1;
1474 p->skb2 = NULL;
1475 }
1476 out:
1477 sock_put(sk);
1478 }
1479
1480 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
1481 u32 group, gfp_t allocation,
1482 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1483 void *filter_data)
1484 {
1485 struct net *net = sock_net(ssk);
1486 struct netlink_broadcast_data info;
1487 struct sock *sk;
1488
1489 skb = netlink_trim(skb, allocation);
1490
1491 info.exclude_sk = ssk;
1492 info.net = net;
1493 info.portid = portid;
1494 info.group = group;
1495 info.failure = 0;
1496 info.delivery_failure = 0;
1497 info.congested = 0;
1498 info.delivered = 0;
1499 info.allocation = allocation;
1500 info.skb = skb;
1501 info.skb2 = NULL;
1502 info.tx_filter = filter;
1503 info.tx_data = filter_data;
1504
1505 /* While we sleep in clone, do not allow to change socket list */
1506
1507 netlink_lock_table();
1508
1509 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1510 do_one_broadcast(sk, &info);
1511
1512 consume_skb(skb);
1513
1514 netlink_unlock_table();
1515
1516 if (info.delivery_failure) {
1517 kfree_skb(info.skb2);
1518 return -ENOBUFS;
1519 }
1520 consume_skb(info.skb2);
1521
1522 if (info.delivered) {
1523 if (info.congested && gfpflags_allow_blocking(allocation))
1524 yield();
1525 return 0;
1526 }
1527 return -ESRCH;
1528 }
1529 EXPORT_SYMBOL(netlink_broadcast_filtered);
1530
1531 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
1532 u32 group, gfp_t allocation)
1533 {
1534 return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
1535 NULL, NULL);
1536 }
1537 EXPORT_SYMBOL(netlink_broadcast);
1538
1539 struct netlink_set_err_data {
1540 struct sock *exclude_sk;
1541 u32 portid;
1542 u32 group;
1543 int code;
1544 };
1545
1546 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1547 {
1548 struct netlink_sock *nlk = nlk_sk(sk);
1549 int ret = 0;
1550
1551 if (sk == p->exclude_sk)
1552 goto out;
1553
1554 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1555 goto out;
1556
1557 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1558 !test_bit(p->group - 1, nlk->groups))
1559 goto out;
1560
1561 if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) {
1562 ret = 1;
1563 goto out;
1564 }
1565
1566 sk->sk_err = p->code;
1567 sk->sk_error_report(sk);
1568 out:
1569 return ret;
1570 }
1571
1572 /**
1573 * netlink_set_err - report error to broadcast listeners
1574 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1575 * @portid: the PORTID of a process that we want to skip (if any)
1576 * @group: the broadcast group that will notice the error
1577 * @code: error code, must be negative (as usual in kernelspace)
1578 *
1579 * This function returns the number of broadcast listeners that have set the
1580 * NETLINK_NO_ENOBUFS socket option.
1581 */
1582 int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
1583 {
1584 struct netlink_set_err_data info;
1585 struct sock *sk;
1586 int ret = 0;
1587
1588 info.exclude_sk = ssk;
1589 info.portid = portid;
1590 info.group = group;
1591 /* sk->sk_err wants a positive error value */
1592 info.code = -code;
1593
1594 read_lock(&nl_table_lock);
1595
1596 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1597 ret += do_one_set_err(sk, &info);
1598
1599 read_unlock(&nl_table_lock);
1600 return ret;
1601 }
1602 EXPORT_SYMBOL(netlink_set_err);
1603
1604 /* must be called with netlink table grabbed */
1605 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1606 unsigned int group,
1607 int is_new)
1608 {
1609 int old, new = !!is_new, subscriptions;
1610
1611 old = test_bit(group - 1, nlk->groups);
1612 subscriptions = nlk->subscriptions - old + new;
1613 if (new)
1614 __set_bit(group - 1, nlk->groups);
1615 else
1616 __clear_bit(group - 1, nlk->groups);
1617 netlink_update_subscriptions(&nlk->sk, subscriptions);
1618 netlink_update_listeners(&nlk->sk);
1619 }
1620
1621 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1622 char __user *optval, unsigned int optlen)
1623 {
1624 struct sock *sk = sock->sk;
1625 struct netlink_sock *nlk = nlk_sk(sk);
1626 unsigned int val = 0;
1627 int err;
1628
1629 if (level != SOL_NETLINK)
1630 return -ENOPROTOOPT;
1631
1632 if (optlen >= sizeof(int) &&
1633 get_user(val, (unsigned int __user *)optval))
1634 return -EFAULT;
1635
1636 switch (optname) {
1637 case NETLINK_PKTINFO:
1638 if (val)
1639 nlk->flags |= NETLINK_F_RECV_PKTINFO;
1640 else
1641 nlk->flags &= ~NETLINK_F_RECV_PKTINFO;
1642 err = 0;
1643 break;
1644 case NETLINK_ADD_MEMBERSHIP:
1645 case NETLINK_DROP_MEMBERSHIP: {
1646 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1647 return -EPERM;
1648 err = netlink_realloc_groups(sk);
1649 if (err)
1650 return err;
1651 if (!val || val - 1 >= nlk->ngroups)
1652 return -EINVAL;
1653 if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
1654 err = nlk->netlink_bind(sock_net(sk), val);
1655 if (err)
1656 return err;
1657 }
1658 netlink_table_grab();
1659 netlink_update_socket_mc(nlk, val,
1660 optname == NETLINK_ADD_MEMBERSHIP);
1661 netlink_table_ungrab();
1662 if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
1663 nlk->netlink_unbind(sock_net(sk), val);
1664
1665 err = 0;
1666 break;
1667 }
1668 case NETLINK_BROADCAST_ERROR:
1669 if (val)
1670 nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR;
1671 else
1672 nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR;
1673 err = 0;
1674 break;
1675 case NETLINK_NO_ENOBUFS:
1676 if (val) {
1677 nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS;
1678 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
1679 wake_up_interruptible(&nlk->wait);
1680 } else {
1681 nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS;
1682 }
1683 err = 0;
1684 break;
1685 case NETLINK_LISTEN_ALL_NSID:
1686 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST))
1687 return -EPERM;
1688
1689 if (val)
1690 nlk->flags |= NETLINK_F_LISTEN_ALL_NSID;
1691 else
1692 nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
1693 err = 0;
1694 break;
1695 case NETLINK_CAP_ACK:
1696 if (val)
1697 nlk->flags |= NETLINK_F_CAP_ACK;
1698 else
1699 nlk->flags &= ~NETLINK_F_CAP_ACK;
1700 err = 0;
1701 break;
1702 case NETLINK_EXT_ACK:
1703 if (val)
1704 nlk->flags |= NETLINK_F_EXT_ACK;
1705 else
1706 nlk->flags &= ~NETLINK_F_EXT_ACK;
1707 err = 0;
1708 break;
1709 case NETLINK_DUMP_STRICT_CHK:
1710 if (val)
1711 nlk->flags |= NETLINK_F_STRICT_CHK;
1712 else
1713 nlk->flags &= ~NETLINK_F_STRICT_CHK;
1714 err = 0;
1715 break;
1716 default:
1717 err = -ENOPROTOOPT;
1718 }
1719 return err;
1720 }
1721
1722 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1723 char __user *optval, int __user *optlen)
1724 {
1725 struct sock *sk = sock->sk;
1726 struct netlink_sock *nlk = nlk_sk(sk);
1727 int len, val, err;
1728
1729 if (level != SOL_NETLINK)
1730 return -ENOPROTOOPT;
1731
1732 if (get_user(len, optlen))
1733 return -EFAULT;
1734 if (len < 0)
1735 return -EINVAL;
1736
1737 switch (optname) {
1738 case NETLINK_PKTINFO:
1739 if (len < sizeof(int))
1740 return -EINVAL;
1741 len = sizeof(int);
1742 val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0;
1743 if (put_user(len, optlen) ||
1744 put_user(val, optval))
1745 return -EFAULT;
1746 err = 0;
1747 break;
1748 case NETLINK_BROADCAST_ERROR:
1749 if (len < sizeof(int))
1750 return -EINVAL;
1751 len = sizeof(int);
1752 val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
1753 if (put_user(len, optlen) ||
1754 put_user(val, optval))
1755 return -EFAULT;
1756 err = 0;
1757 break;
1758 case NETLINK_NO_ENOBUFS:
1759 if (len < sizeof(int))
1760 return -EINVAL;
1761 len = sizeof(int);
1762 val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
1763 if (put_user(len, optlen) ||
1764 put_user(val, optval))
1765 return -EFAULT;
1766 err = 0;
1767 break;
1768 case NETLINK_LIST_MEMBERSHIPS: {
1769 int pos, idx, shift;
1770
1771 err = 0;
1772 netlink_lock_table();
1773 for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
1774 if (len - pos < sizeof(u32))
1775 break;
1776
1777 idx = pos / sizeof(unsigned long);
1778 shift = (pos % sizeof(unsigned long)) * 8;
1779 if (put_user((u32)(nlk->groups[idx] >> shift),
1780 (u32 __user *)(optval + pos))) {
1781 err = -EFAULT;
1782 break;
1783 }
1784 }
1785 if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
1786 err = -EFAULT;
1787 netlink_unlock_table();
1788 break;
1789 }
1790 case NETLINK_CAP_ACK:
1791 if (len < sizeof(int))
1792 return -EINVAL;
1793 len = sizeof(int);
1794 val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
1795 if (put_user(len, optlen) ||
1796 put_user(val, optval))
1797 return -EFAULT;
1798 err = 0;
1799 break;
1800 case NETLINK_EXT_ACK:
1801 if (len < sizeof(int))
1802 return -EINVAL;
1803 len = sizeof(int);
1804 val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
1805 if (put_user(len, optlen) || put_user(val, optval))
1806 return -EFAULT;
1807 err = 0;
1808 break;
1809 case NETLINK_DUMP_STRICT_CHK:
1810 if (len < sizeof(int))
1811 return -EINVAL;
1812 len = sizeof(int);
1813 val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0;
1814 if (put_user(len, optlen) || put_user(val, optval))
1815 return -EFAULT;
1816 err = 0;
1817 break;
1818 default:
1819 err = -ENOPROTOOPT;
1820 }
1821 return err;
1822 }
1823
1824 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1825 {
1826 struct nl_pktinfo info;
1827
1828 info.group = NETLINK_CB(skb).dst_group;
1829 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1830 }
1831
1832 static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg,
1833 struct sk_buff *skb)
1834 {
1835 if (!NETLINK_CB(skb).nsid_is_set)
1836 return;
1837
1838 put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int),
1839 &NETLINK_CB(skb).nsid);
1840 }
1841
1842 static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1843 {
1844 struct sock *sk = sock->sk;
1845 struct netlink_sock *nlk = nlk_sk(sk);
1846 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1847 u32 dst_portid;
1848 u32 dst_group;
1849 struct sk_buff *skb;
1850 int err;
1851 struct scm_cookie scm;
1852 u32 netlink_skb_flags = 0;
1853
1854 if (msg->msg_flags&MSG_OOB)
1855 return -EOPNOTSUPP;
1856
1857 err = scm_send(sock, msg, &scm, true);
1858 if (err < 0)
1859 return err;
1860
1861 if (msg->msg_namelen) {
1862 err = -EINVAL;
1863 if (msg->msg_namelen < sizeof(struct sockaddr_nl))
1864 goto out;
1865 if (addr->nl_family != AF_NETLINK)
1866 goto out;
1867 dst_portid = addr->nl_pid;
1868 dst_group = ffs(addr->nl_groups);
1869 err = -EPERM;
1870 if ((dst_group || dst_portid) &&
1871 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1872 goto out;
1873 netlink_skb_flags |= NETLINK_SKB_DST;
1874 } else {
1875 dst_portid = nlk->dst_portid;
1876 dst_group = nlk->dst_group;
1877 }
1878
1879 if (!nlk->bound) {
1880 err = netlink_autobind(sock);
1881 if (err)
1882 goto out;
1883 } else {
1884 /* Ensure nlk is hashed and visible. */
1885 smp_rmb();
1886 }
1887
1888 err = -EMSGSIZE;
1889 if (len > sk->sk_sndbuf - 32)
1890 goto out;
1891 err = -ENOBUFS;
1892 skb = netlink_alloc_large_skb(len, dst_group);
1893 if (skb == NULL)
1894 goto out;
1895
1896 NETLINK_CB(skb).portid = nlk->portid;
1897 NETLINK_CB(skb).dst_group = dst_group;
1898 NETLINK_CB(skb).creds = scm.creds;
1899 NETLINK_CB(skb).flags = netlink_skb_flags;
1900
1901 err = -EFAULT;
1902 if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1903 kfree_skb(skb);
1904 goto out;
1905 }
1906
1907 err = security_netlink_send(sk, skb);
1908 if (err) {
1909 kfree_skb(skb);
1910 goto out;
1911 }
1912
1913 if (dst_group) {
1914 refcount_inc(&skb->users);
1915 netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
1916 }
1917 err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
1918
1919 out:
1920 scm_destroy(&scm);
1921 return err;
1922 }
1923
1924 static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1925 int flags)
1926 {
1927 struct scm_cookie scm;
1928 struct sock *sk = sock->sk;
1929 struct netlink_sock *nlk = nlk_sk(sk);
1930 int noblock = flags&MSG_DONTWAIT;
1931 size_t copied;
1932 struct sk_buff *skb, *data_skb;
1933 int err, ret;
1934
1935 if (flags&MSG_OOB)
1936 return -EOPNOTSUPP;
1937
1938 copied = 0;
1939
1940 skb = skb_recv_datagram(sk, flags, noblock, &err);
1941 if (skb == NULL)
1942 goto out;
1943
1944 data_skb = skb;
1945
1946 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1947 if (unlikely(skb_shinfo(skb)->frag_list)) {
1948 /*
1949 * If this skb has a frag_list, then here that means that we
1950 * will have to use the frag_list skb's data for compat tasks
1951 * and the regular skb's data for normal (non-compat) tasks.
1952 *
1953 * If we need to send the compat skb, assign it to the
1954 * 'data_skb' variable so that it will be used below for data
1955 * copying. We keep 'skb' for everything else, including
1956 * freeing both later.
1957 */
1958 if (flags & MSG_CMSG_COMPAT)
1959 data_skb = skb_shinfo(skb)->frag_list;
1960 }
1961 #endif
1962
1963 /* Record the max length of recvmsg() calls for future allocations */
1964 nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
1965 nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
1966 SKB_WITH_OVERHEAD(32768));
1967
1968 copied = data_skb->len;
1969 if (len < copied) {
1970 msg->msg_flags |= MSG_TRUNC;
1971 copied = len;
1972 }
1973
1974 skb_reset_transport_header(data_skb);
1975 err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
1976
1977 if (msg->msg_name) {
1978 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1979 addr->nl_family = AF_NETLINK;
1980 addr->nl_pad = 0;
1981 addr->nl_pid = NETLINK_CB(skb).portid;
1982 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1983 msg->msg_namelen = sizeof(*addr);
1984 }
1985
1986 if (nlk->flags & NETLINK_F_RECV_PKTINFO)
1987 netlink_cmsg_recv_pktinfo(msg, skb);
1988 if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
1989 netlink_cmsg_listen_all_nsid(sk, msg, skb);
1990
1991 memset(&scm, 0, sizeof(scm));
1992 scm.creds = *NETLINK_CREDS(skb);
1993 if (flags & MSG_TRUNC)
1994 copied = data_skb->len;
1995
1996 skb_free_datagram(sk, skb);
1997
1998 if (nlk->cb_running &&
1999 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
2000 ret = netlink_dump(sk);
2001 if (ret) {
2002 sk->sk_err = -ret;
2003 sk->sk_error_report(sk);
2004 }
2005 }
2006
2007 scm_recv(sock, msg, &scm, flags);
2008 out:
2009 netlink_rcv_wake(sk);
2010 return err ? : copied;
2011 }
2012
2013 static void netlink_data_ready(struct sock *sk)
2014 {
2015 BUG();
2016 }
2017
2018 /*
2019 * We export these functions to other modules. They provide a
2020 * complete set of kernel non-blocking support for message
2021 * queueing.
2022 */
2023
2024 struct sock *
2025 __netlink_kernel_create(struct net *net, int unit, struct module *module,
2026 struct netlink_kernel_cfg *cfg)
2027 {
2028 struct socket *sock;
2029 struct sock *sk;
2030 struct netlink_sock *nlk;
2031 struct listeners *listeners = NULL;
2032 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
2033 unsigned int groups;
2034
2035 BUG_ON(!nl_table);
2036
2037 if (unit < 0 || unit >= MAX_LINKS)
2038 return NULL;
2039
2040 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
2041 return NULL;
2042
2043 if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
2044 goto out_sock_release_nosk;
2045
2046 sk = sock->sk;
2047
2048 if (!cfg || cfg->groups < 32)
2049 groups = 32;
2050 else
2051 groups = cfg->groups;
2052
2053 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2054 if (!listeners)
2055 goto out_sock_release;
2056
2057 sk->sk_data_ready = netlink_data_ready;
2058 if (cfg && cfg->input)
2059 nlk_sk(sk)->netlink_rcv = cfg->input;
2060
2061 if (netlink_insert(sk, 0))
2062 goto out_sock_release;
2063
2064 nlk = nlk_sk(sk);
2065 nlk->flags |= NETLINK_F_KERNEL_SOCKET;
2066
2067 netlink_table_grab();
2068 if (!nl_table[unit].registered) {
2069 nl_table[unit].groups = groups;
2070 rcu_assign_pointer(nl_table[unit].listeners, listeners);
2071 nl_table[unit].cb_mutex = cb_mutex;
2072 nl_table[unit].module = module;
2073 if (cfg) {
2074 nl_table[unit].bind = cfg->bind;
2075 nl_table[unit].unbind = cfg->unbind;
2076 nl_table[unit].flags = cfg->flags;
2077 if (cfg->compare)
2078 nl_table[unit].compare = cfg->compare;
2079 }
2080 nl_table[unit].registered = 1;
2081 } else {
2082 kfree(listeners);
2083 nl_table[unit].registered++;
2084 }
2085 netlink_table_ungrab();
2086 return sk;
2087
2088 out_sock_release:
2089 kfree(listeners);
2090 netlink_kernel_release(sk);
2091 return NULL;
2092
2093 out_sock_release_nosk:
2094 sock_release(sock);
2095 return NULL;
2096 }
2097 EXPORT_SYMBOL(__netlink_kernel_create);
2098
2099 void
2100 netlink_kernel_release(struct sock *sk)
2101 {
2102 if (sk == NULL || sk->sk_socket == NULL)
2103 return;
2104
2105 sock_release(sk->sk_socket);
2106 }
2107 EXPORT_SYMBOL(netlink_kernel_release);
2108
2109 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
2110 {
2111 struct listeners *new, *old;
2112 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
2113
2114 if (groups < 32)
2115 groups = 32;
2116
2117 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
2118 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
2119 if (!new)
2120 return -ENOMEM;
2121 old = nl_deref_protected(tbl->listeners);
2122 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
2123 rcu_assign_pointer(tbl->listeners, new);
2124
2125 kfree_rcu(old, rcu);
2126 }
2127 tbl->groups = groups;
2128
2129 return 0;
2130 }
2131
2132 /**
2133 * netlink_change_ngroups - change number of multicast groups
2134 *
2135 * This changes the number of multicast groups that are available
2136 * on a certain netlink family. Note that it is not possible to
2137 * change the number of groups to below 32. Also note that it does
2138 * not implicitly call netlink_clear_multicast_users() when the
2139 * number of groups is reduced.
2140 *
2141 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2142 * @groups: The new number of groups.
2143 */
2144 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
2145 {
2146 int err;
2147
2148 netlink_table_grab();
2149 err = __netlink_change_ngroups(sk, groups);
2150 netlink_table_ungrab();
2151
2152 return err;
2153 }
2154
2155 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
2156 {
2157 struct sock *sk;
2158 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
2159
2160 sk_for_each_bound(sk, &tbl->mc_list)
2161 netlink_update_socket_mc(nlk_sk(sk), group, 0);
2162 }
2163
2164 struct nlmsghdr *
2165 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
2166 {
2167 struct nlmsghdr *nlh;
2168 int size = nlmsg_msg_size(len);
2169
2170 nlh = skb_put(skb, NLMSG_ALIGN(size));
2171 nlh->nlmsg_type = type;
2172 nlh->nlmsg_len = size;
2173 nlh->nlmsg_flags = flags;
2174 nlh->nlmsg_pid = portid;
2175 nlh->nlmsg_seq = seq;
2176 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
2177 memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
2178 return nlh;
2179 }
2180 EXPORT_SYMBOL(__nlmsg_put);
2181
2182 /*
2183 * It looks a bit ugly.
2184 * It would be better to create kernel thread.
2185 */
2186
2187 static int netlink_dump(struct sock *sk)
2188 {
2189 struct netlink_sock *nlk = nlk_sk(sk);
2190 struct netlink_ext_ack extack = {};
2191 struct netlink_callback *cb;
2192 struct sk_buff *skb = NULL;
2193 struct nlmsghdr *nlh;
2194 struct module *module;
2195 int err = -ENOBUFS;
2196 int alloc_min_size;
2197 int alloc_size;
2198
2199 mutex_lock(nlk->cb_mutex);
2200 if (!nlk->cb_running) {
2201 err = -EINVAL;
2202 goto errout_skb;
2203 }
2204
2205 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2206 goto errout_skb;
2207
2208 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2209 * required, but it makes sense to _attempt_ a 16K bytes allocation
2210 * to reduce number of system calls on dump operations, if user
2211 * ever provided a big enough buffer.
2212 */
2213 cb = &nlk->cb;
2214 alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
2215
2216 if (alloc_min_size < nlk->max_recvmsg_len) {
2217 alloc_size = nlk->max_recvmsg_len;
2218 skb = alloc_skb(alloc_size,
2219 (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
2220 __GFP_NOWARN | __GFP_NORETRY);
2221 }
2222 if (!skb) {
2223 alloc_size = alloc_min_size;
2224 skb = alloc_skb(alloc_size, GFP_KERNEL);
2225 }
2226 if (!skb)
2227 goto errout_skb;
2228
2229 /* Trim skb to allocated size. User is expected to provide buffer as
2230 * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
2231 * netlink_recvmsg())). dump will pack as many smaller messages as
2232 * could fit within the allocated skb. skb is typically allocated
2233 * with larger space than required (could be as much as near 2x the
2234 * requested size with align to next power of 2 approach). Allowing
2235 * dump to use the excess space makes it difficult for a user to have a
2236 * reasonable static buffer based on the expected largest dump of a
2237 * single netdev. The outcome is MSG_TRUNC error.
2238 */
2239 skb_reserve(skb, skb_tailroom(skb) - alloc_size);
2240 netlink_skb_set_owner_r(skb, sk);
2241
2242 if (nlk->dump_done_errno > 0) {
2243 cb->extack = &extack;
2244 nlk->dump_done_errno = cb->dump(skb, cb);
2245 cb->extack = NULL;
2246 }
2247
2248 if (nlk->dump_done_errno > 0 ||
2249 skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
2250 mutex_unlock(nlk->cb_mutex);
2251
2252 if (sk_filter(sk, skb))
2253 kfree_skb(skb);
2254 else
2255 __netlink_sendskb(sk, skb);
2256 return 0;
2257 }
2258
2259 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE,
2260 sizeof(nlk->dump_done_errno),
2261 NLM_F_MULTI | cb->answer_flags);
2262 if (WARN_ON(!nlh))
2263 goto errout_skb;
2264
2265 nl_dump_check_consistent(cb, nlh);
2266
2267 memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
2268 sizeof(nlk->dump_done_errno));
2269
2270 if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {
2271 nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
2272 if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))
2273 nlmsg_end(skb, nlh);
2274 }
2275
2276 if (sk_filter(sk, skb))
2277 kfree_skb(skb);
2278 else
2279 __netlink_sendskb(sk, skb);
2280
2281 if (cb->done)
2282 cb->done(cb);
2283
2284 nlk->cb_running = false;
2285 module = cb->module;
2286 skb = cb->skb;
2287 mutex_unlock(nlk->cb_mutex);
2288 module_put(module);
2289 consume_skb(skb);
2290 return 0;
2291
2292 errout_skb:
2293 mutex_unlock(nlk->cb_mutex);
2294 kfree_skb(skb);
2295 return err;
2296 }
2297
2298 int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
2299 const struct nlmsghdr *nlh,
2300 struct netlink_dump_control *control)
2301 {
2302 struct netlink_sock *nlk, *nlk2;
2303 struct netlink_callback *cb;
2304 struct sock *sk;
2305 int ret;
2306
2307 refcount_inc(&skb->users);
2308
2309 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
2310 if (sk == NULL) {
2311 ret = -ECONNREFUSED;
2312 goto error_free;
2313 }
2314
2315 nlk = nlk_sk(sk);
2316 mutex_lock(nlk->cb_mutex);
2317 /* A dump is in progress... */
2318 if (nlk->cb_running) {
2319 ret = -EBUSY;
2320 goto error_unlock;
2321 }
2322 /* add reference of module which cb->dump belongs to */
2323 if (!try_module_get(control->module)) {
2324 ret = -EPROTONOSUPPORT;
2325 goto error_unlock;
2326 }
2327
2328 cb = &nlk->cb;
2329 memset(cb, 0, sizeof(*cb));
2330 cb->dump = control->dump;
2331 cb->done = control->done;
2332 cb->nlh = nlh;
2333 cb->data = control->data;
2334 cb->module = control->module;
2335 cb->min_dump_alloc = control->min_dump_alloc;
2336 cb->skb = skb;
2337
2338 nlk2 = nlk_sk(NETLINK_CB(skb).sk);
2339 cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK);
2340
2341 if (control->start) {
2342 ret = control->start(cb);
2343 if (ret)
2344 goto error_put;
2345 }
2346
2347 nlk->cb_running = true;
2348 nlk->dump_done_errno = INT_MAX;
2349
2350 mutex_unlock(nlk->cb_mutex);
2351
2352 ret = netlink_dump(sk);
2353
2354 sock_put(sk);
2355
2356 if (ret)
2357 return ret;
2358
2359 /* We successfully started a dump, by returning -EINTR we
2360 * signal not to send ACK even if it was requested.
2361 */
2362 return -EINTR;
2363
2364 error_put:
2365 module_put(control->module);
2366 error_unlock:
2367 sock_put(sk);
2368 mutex_unlock(nlk->cb_mutex);
2369 error_free:
2370 kfree_skb(skb);
2371 return ret;
2372 }
2373 EXPORT_SYMBOL(__netlink_dump_start);
2374
2375 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
2376 const struct netlink_ext_ack *extack)
2377 {
2378 struct sk_buff *skb;
2379 struct nlmsghdr *rep;
2380 struct nlmsgerr *errmsg;
2381 size_t payload = sizeof(*errmsg);
2382 size_t tlvlen = 0;
2383 struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
2384 unsigned int flags = 0;
2385 bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK;
2386
2387 /* Error messages get the original request appened, unless the user
2388 * requests to cap the error message, and get extra error data if
2389 * requested.
2390 */
2391 if (nlk_has_extack && extack && extack->_msg)
2392 tlvlen += nla_total_size(strlen(extack->_msg) + 1);
2393
2394 if (err) {
2395 if (!(nlk->flags & NETLINK_F_CAP_ACK))
2396 payload += nlmsg_len(nlh);
2397 else
2398 flags |= NLM_F_CAPPED;
2399 if (nlk_has_extack && extack && extack->bad_attr)
2400 tlvlen += nla_total_size(sizeof(u32));
2401 } else {
2402 flags |= NLM_F_CAPPED;
2403
2404 if (nlk_has_extack && extack && extack->cookie_len)
2405 tlvlen += nla_total_size(extack->cookie_len);
2406 }
2407
2408 if (tlvlen)
2409 flags |= NLM_F_ACK_TLVS;
2410
2411 skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
2412 if (!skb) {
2413 NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
2414 NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk);
2415 return;
2416 }
2417
2418 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2419 NLMSG_ERROR, payload, flags);
2420 errmsg = nlmsg_data(rep);
2421 errmsg->error = err;
2422 memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
2423
2424 if (nlk_has_extack && extack) {
2425 if (extack->_msg) {
2426 WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
2427 extack->_msg));
2428 }
2429 if (err) {
2430 if (extack->bad_attr &&
2431 !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
2432 (u8 *)extack->bad_attr >= in_skb->data +
2433 in_skb->len))
2434 WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
2435 (u8 *)extack->bad_attr -
2436 in_skb->data));
2437 } else {
2438 if (extack->cookie_len)
2439 WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
2440 extack->cookie_len,
2441 extack->cookie));
2442 }
2443 }
2444
2445 nlmsg_end(skb, rep);
2446
2447 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
2448 }
2449 EXPORT_SYMBOL(netlink_ack);
2450
2451 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
2452 struct nlmsghdr *,
2453 struct netlink_ext_ack *))
2454 {
2455 struct netlink_ext_ack extack;
2456 struct nlmsghdr *nlh;
2457 int err;
2458
2459 while (skb->len >= nlmsg_total_size(0)) {
2460 int msglen;
2461
2462 memset(&extack, 0, sizeof(extack));
2463 nlh = nlmsg_hdr(skb);
2464 err = 0;
2465
2466 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
2467 return 0;
2468
2469 /* Only requests are handled by the kernel */
2470 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
2471 goto ack;
2472
2473 /* Skip control messages */
2474 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
2475 goto ack;
2476
2477 err = cb(skb, nlh, &extack);
2478 if (err == -EINTR)
2479 goto skip;
2480
2481 ack:
2482 if (nlh->nlmsg_flags & NLM_F_ACK || err)
2483 netlink_ack(skb, nlh, err, &extack);
2484
2485 skip:
2486 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
2487 if (msglen > skb->len)
2488 msglen = skb->len;
2489 skb_pull(skb, msglen);
2490 }
2491
2492 return 0;
2493 }
2494 EXPORT_SYMBOL(netlink_rcv_skb);
2495
2496 /**
2497 * nlmsg_notify - send a notification netlink message
2498 * @sk: netlink socket to use
2499 * @skb: notification message
2500 * @portid: destination netlink portid for reports or 0
2501 * @group: destination multicast group or 0
2502 * @report: 1 to report back, 0 to disable
2503 * @flags: allocation flags
2504 */
2505 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
2506 unsigned int group, int report, gfp_t flags)
2507 {
2508 int err = 0;
2509
2510 if (group) {
2511 int exclude_portid = 0;
2512
2513 if (report) {
2514 refcount_inc(&skb->users);
2515 exclude_portid = portid;
2516 }
2517
2518 /* errors reported via destination sk->sk_err, but propagate
2519 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2520 err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
2521 }
2522
2523 if (report) {
2524 int err2;
2525
2526 err2 = nlmsg_unicast(sk, skb, portid);
2527 if (!err || err == -ESRCH)
2528 err = err2;
2529 }
2530
2531 return err;
2532 }
2533 EXPORT_SYMBOL(nlmsg_notify);
2534
2535 #ifdef CONFIG_PROC_FS
2536 struct nl_seq_iter {
2537 struct seq_net_private p;
2538 struct rhashtable_iter hti;
2539 int link;
2540 };
2541
2542 static int netlink_walk_start(struct nl_seq_iter *iter)
2543 {
2544 int err;
2545
2546 err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti,
2547 GFP_KERNEL);
2548 if (err) {
2549 iter->link = MAX_LINKS;
2550 return err;
2551 }
2552
2553 rhashtable_walk_start(&iter->hti);
2554
2555 return 0;
2556 }
2557
2558 static void netlink_walk_stop(struct nl_seq_iter *iter)
2559 {
2560 rhashtable_walk_stop(&iter->hti);
2561 rhashtable_walk_exit(&iter->hti);
2562 }
2563
2564 static void *__netlink_seq_next(struct seq_file *seq)
2565 {
2566 struct nl_seq_iter *iter = seq->private;
2567 struct netlink_sock *nlk;
2568
2569 do {
2570 for (;;) {
2571 int err;
2572
2573 nlk = rhashtable_walk_next(&iter->hti);
2574
2575 if (IS_ERR(nlk)) {
2576 if (PTR_ERR(nlk) == -EAGAIN)
2577 continue;
2578
2579 return nlk;
2580 }
2581
2582 if (nlk)
2583 break;
2584
2585 netlink_walk_stop(iter);
2586 if (++iter->link >= MAX_LINKS)
2587 return NULL;
2588
2589 err = netlink_walk_start(iter);
2590 if (err)
2591 return ERR_PTR(err);
2592 }
2593 } while (sock_net(&nlk->sk) != seq_file_net(seq));
2594
2595 return nlk;
2596 }
2597
2598 static void *netlink_seq_start(struct seq_file *seq, loff_t *posp)
2599 {
2600 struct nl_seq_iter *iter = seq->private;
2601 void *obj = SEQ_START_TOKEN;
2602 loff_t pos;
2603 int err;
2604
2605 iter->link = 0;
2606
2607 err = netlink_walk_start(iter);
2608 if (err)
2609 return ERR_PTR(err);
2610
2611 for (pos = *posp; pos && obj && !IS_ERR(obj); pos--)
2612 obj = __netlink_seq_next(seq);
2613
2614 return obj;
2615 }
2616
2617 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2618 {
2619 ++*pos;
2620 return __netlink_seq_next(seq);
2621 }
2622
2623 static void netlink_seq_stop(struct seq_file *seq, void *v)
2624 {
2625 struct nl_seq_iter *iter = seq->private;
2626
2627 if (iter->link >= MAX_LINKS)
2628 return;
2629
2630 netlink_walk_stop(iter);
2631 }
2632
2633
2634 static int netlink_seq_show(struct seq_file *seq, void *v)
2635 {
2636 if (v == SEQ_START_TOKEN) {
2637 seq_puts(seq,
2638 "sk Eth Pid Groups "
2639 "Rmem Wmem Dump Locks Drops Inode\n");
2640 } else {
2641 struct sock *s = v;
2642 struct netlink_sock *nlk = nlk_sk(s);
2643
2644 seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8d %-8lu\n",
2645 s,
2646 s->sk_protocol,
2647 nlk->portid,
2648 nlk->groups ? (u32)nlk->groups[0] : 0,
2649 sk_rmem_alloc_get(s),
2650 sk_wmem_alloc_get(s),
2651 nlk->cb_running,
2652 refcount_read(&s->sk_refcnt),
2653 atomic_read(&s->sk_drops),
2654 sock_i_ino(s)
2655 );
2656
2657 }
2658 return 0;
2659 }
2660
2661 static const struct seq_operations netlink_seq_ops = {
2662 .start = netlink_seq_start,
2663 .next = netlink_seq_next,
2664 .stop = netlink_seq_stop,
2665 .show = netlink_seq_show,
2666 };
2667 #endif
2668
2669 int netlink_register_notifier(struct notifier_block *nb)
2670 {
2671 return blocking_notifier_chain_register(&netlink_chain, nb);
2672 }
2673 EXPORT_SYMBOL(netlink_register_notifier);
2674
2675 int netlink_unregister_notifier(struct notifier_block *nb)
2676 {
2677 return blocking_notifier_chain_unregister(&netlink_chain, nb);
2678 }
2679 EXPORT_SYMBOL(netlink_unregister_notifier);
2680
2681 static const struct proto_ops netlink_ops = {
2682 .family = PF_NETLINK,
2683 .owner = THIS_MODULE,
2684 .release = netlink_release,
2685 .bind = netlink_bind,
2686 .connect = netlink_connect,
2687 .socketpair = sock_no_socketpair,
2688 .accept = sock_no_accept,
2689 .getname = netlink_getname,
2690 .poll = datagram_poll,
2691 .ioctl = netlink_ioctl,
2692 .listen = sock_no_listen,
2693 .shutdown = sock_no_shutdown,
2694 .setsockopt = netlink_setsockopt,
2695 .getsockopt = netlink_getsockopt,
2696 .sendmsg = netlink_sendmsg,
2697 .recvmsg = netlink_recvmsg,
2698 .mmap = sock_no_mmap,
2699 .sendpage = sock_no_sendpage,
2700 };
2701
2702 static const struct net_proto_family netlink_family_ops = {
2703 .family = PF_NETLINK,
2704 .create = netlink_create,
2705 .owner = THIS_MODULE, /* for consistency 8) */
2706 };
2707
2708 static int __net_init netlink_net_init(struct net *net)
2709 {
2710 #ifdef CONFIG_PROC_FS
2711 if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops,
2712 sizeof(struct nl_seq_iter)))
2713 return -ENOMEM;
2714 #endif
2715 return 0;
2716 }
2717
2718 static void __net_exit netlink_net_exit(struct net *net)
2719 {
2720 #ifdef CONFIG_PROC_FS
2721 remove_proc_entry("netlink", net->proc_net);
2722 #endif
2723 }
2724
2725 static void __init netlink_add_usersock_entry(void)
2726 {
2727 struct listeners *listeners;
2728 int groups = 32;
2729
2730 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2731 if (!listeners)
2732 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2733
2734 netlink_table_grab();
2735
2736 nl_table[NETLINK_USERSOCK].groups = groups;
2737 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2738 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2739 nl_table[NETLINK_USERSOCK].registered = 1;
2740 nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
2741
2742 netlink_table_ungrab();
2743 }
2744
2745 static struct pernet_operations __net_initdata netlink_net_ops = {
2746 .init = netlink_net_init,
2747 .exit = netlink_net_exit,
2748 };
2749
2750 static inline u32 netlink_hash(const void *data, u32 len, u32 seed)
2751 {
2752 const struct netlink_sock *nlk = data;
2753 struct netlink_compare_arg arg;
2754
2755 netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid);
2756 return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed);
2757 }
2758
2759 static const struct rhashtable_params netlink_rhashtable_params = {
2760 .head_offset = offsetof(struct netlink_sock, node),
2761 .key_len = netlink_compare_arg_len,
2762 .obj_hashfn = netlink_hash,
2763 .obj_cmpfn = netlink_compare,
2764 .automatic_shrinking = true,
2765 };
2766
2767 static int __init netlink_proto_init(void)
2768 {
2769 int i;
2770 int err = proto_register(&netlink_proto, 0);
2771
2772 if (err != 0)
2773 goto out;
2774
2775 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
2776
2777 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2778 if (!nl_table)
2779 goto panic;
2780
2781 for (i = 0; i < MAX_LINKS; i++) {
2782 if (rhashtable_init(&nl_table[i].hash,
2783 &netlink_rhashtable_params) < 0) {
2784 while (--i > 0)
2785 rhashtable_destroy(&nl_table[i].hash);
2786 kfree(nl_table);
2787 goto panic;
2788 }
2789 }
2790
2791 netlink_add_usersock_entry();
2792
2793 sock_register(&netlink_family_ops);
2794 register_pernet_subsys(&netlink_net_ops);
2795 register_pernet_subsys(&netlink_tap_net_ops);
2796 /* The netlink device handler may be needed early. */
2797 rtnetlink_init();
2798 out:
2799 return err;
2800 panic:
2801 panic("netlink_init: Cannot allocate nl_table\n");
2802 }
2803
2804 core_initcall(netlink_proto_init);
Linux with added FPC-III support